[PARISC] Fix uniprocessor build by dummying smp_send_all_nop()

Since irq.c uses smp_send_all_nop, we must define it for UP builds
as well. Make it a static inline so it gets optimized away. This forces
irq.c to include <asm/smp.h> though.
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

arch/parisc/kernel/irq.c

@@ -31,6 +31,8 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
+#include <asm/smp.h>
+
 #undef PARISC_IRQ_CR16_COUNTS
 
 extern irqreturn_t timer_interrupt(int, void *, struct pt_regs *);

include/asm-parisc/smp.h

@@ -54,7 +54,11 @@ extern unsigned long cpu_present_mask;
 
 #define raw_smp_processor_id()	(current_thread_info()->cpu)
 
-#endif /* CONFIG_SMP */
+#else /* CONFIG_SMP */
+
+static inline void smp_send_all_nop(void) { return; }
+
+#endif
 
 #define NO_PROC_ID		0xFF		/* No processor magic marker */
 #define ANY_PROC_ID		0xFF		/* Any processor magic marker */